1. Field of the Invention
The invention relates to depth detection. More specifically, the invention relates to using individual pixels or elementary groups of pixels to determine distance from a reference.
2. Background
Various 3D imaging techniques exist for capturing three dimensional representations of three dimensional objects. To effect these captures it is necessary to determine depth from a reference point for each point represented. One way this has been done in the past is using a laser which sweeps over the target object. As the laser sweeps, the spot reflects off the object and strikes an image sensing array (“ISA”) where the spot strikes the ISA and indicates the depth of that point on the target from which it was reflected. Only a single depth measurement is captured for each captured period using this method. If we assume an ISA has 5,000 pixels, this implies a ratio of 1 to 5,000 in terms of depth measurements per pixel.
Another common technique is to capture a projected pattern and interpret the distortion of the projected pattern. Using this technique, it is necessary to contextualize the distortion with the readings from adjacent pixels in order to identify and interpret a depth measurement for a particular location. While this technique improves the depth measurement per pixel ratio over the laser method discussed above, each measurement is dependent on the values captured by surrounding pixels and the ratio does not approach 1 to 1.
Ultimately, the maximum resolution of a 3D image captured during a period of time is limited by the number of depth measurements that can be derived during that time period from the ISA. Maximum resolution and speed is achieved where each pixel provides a depth measurement for each capture period.